[官方预报]
1502號颱風“ 海高斯”官方機構預報專帖

WDPN31 PGTW 090300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 02W (HIGOS) WARNING NR 08//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 02W (HIGOS), LOCATED APPROXIMATELY 677 NM EAST OF
ANDERSEN AFB, GUAM, HAS TRACKED WEST-NORTHWESTWARD AT 03 KNOTS OVER
THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS
CONTINUED CONSOLIDATION OF THE CENTRAL CONVECTION WITH FEEDER BANDS
WRAPPING TIGHTER INTO THE WELL-DEFINED LOW LEVEL CIRCULATION CENTER
(LLCC). THIS IS ALSO CORROBORATED BY A 082055Z SSMIS 91 GHZ MICROWAVE
IMAGE SHOWING DEEP CONVECTIVE BANDING LOCATED ALONG THE NORTHERN AND
WESTERN PERIPHERIES OF THE SYSTEM. THE CURRENT POSITION IS BASED ON
THE PGTW FIX AND AFOREMENTIONED MICROWAVE IMAGE WITH FAIR CONFIDENCE.
THE CURRENT INTENSITY IS BASED ON AN OVERALL ASSESSMENT OF AGENCY
DVORAK ESTIMATES AND REFLECTS THE IMPROVED CENTRAL CONVECTION. THE
UPPER LEVEL ENVIRONMENT REMAINS UNCHANGED WITH LOW TO MODERATE (10 TO
20 KNOT) VERTICAL WIND SHEAR (VWS) BEING OFFSET BY VIGOROUS POLEWARD
OUTFLOW. TY 02W REMAINS IN A COMPETING STEERING ENVIRONMENT BETWEEN
TWO MID- TO HIGH-LEVEL SUB-TROPICAL RIDGES (STR), ONE TO THE EAST AND
THE OTHER TO THE WEST OF THE CYCLONE, LEADING TO THE QUASI-STATIONARY
MOVEMENT.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TY HIGOS WILL CONTINUE ON A SLOW WEST-NORTHWESTWARD TRACK OVER
THE NEXT 6 TO 12 HOURS UNTIL THE STR EAST OF THE SYSTEM TAKES OVER
AS THE DOMINANT STEERING MECHANISM. WITH THE DECREASE IN FORWARD
MOTION, FAVORABLE UPPER-LEVEL CONDITIONS WILL PERSIST OVER THE
SYSTEM FOR THE NEXT 24 HOURS ALLOWING TY 02W TO CONTINUE ITS
INTENSIFICATION, REACHING A PEAK OF 85 KNOTS BY TAU 24. BEYOND TAU
24, TY HIGOS WILL BEGIN TO WEAKEN AS IT ENCOUNTERS INCREASED (20 TO
30 KNOT) SOUTHWESTERLY VWS. AFTER TAU 48, THE SYSTEM WILL TURN
POLEWARD AS IT ROUNDS THE SOUTHWESTERN PERIPHERY OF THE STR AND
ENTERS AN UNFAVORABLE ENVIRONMENT WITH 40 TO 50 KNOT VWS, DECREASING
SEA SURFACE TEMPERATURE, AND REDUCED OCEAN HEAT CONTENT.
C. AFTER TAU 72, THE SYSTEM WILL RAPIDLY WEAKEN AS VWS INCREASES
ABOVE 50 KNOTS LEADING TO DISSIPATION BY THE END OF THE FORECAST
PERIOD. DYNAMIC MODEL GUIDANCE HAS COME INTO BETTER AGREEMENT
THROUGH TAU 72 WITH A 250NM SPREAD AFTERWARDS. BEYOND TAU 72, GFS
AND JENS EMBED THE SYSTEM IN THE MID-LATITUDE WESTERLIES, WHILE THE
REMAINING GUIDANCE DEPICTS DISSIPATION AT TAU 120. BASED ON THE
ZONAL FLOW AND LACK OF TEMPERATURE ADVECTION IN THE WESTERLY FLOW,
JTWC EXPECTS THE SYSTEM TO DISSIPATE. DUE TO CONTINUED UNCERTAINTY
IN THE QUASI-STATIONARY MOTION AND THE EXTENDED MODEL GUIDANCE, THE
JTWC FORECAST REMAINS LOW.//
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WDPN31 PGTW 100300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 02W (HIGOS) WARNING NR 12//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TYPHOON (TY) 02W (HIGOS), LOCATED APPROXIMATELY 394 NM NORTH-
NORTHEAST OF CHUUK, HAS TRACKED NORTHWESTWARD AT 06 KNOTS OVER THE
PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY
CONTINUES TO DEPICT PERSISTENT DEEP CENTRAL CONVECTION OBSCURING A
CONSOLIDATING LOW-LEVEL CIRCULATION CENTER. THE CURRENT POSITION IS
BASED ON THE EIR LOOP AS WELL AS A 091751Z SSMIS 91 GHZ SATELLITE
IMAGE WITH GOOD CONFIDENCE. THE CURRENT INTENSITY OF 75 KNOTS IS
BASED ON A COMPOSITE OF ALL AGENCIES DVORAK INTENSITY ESTIMATES.
UPPER-LEVEL ANALYSIS SHOWS THE SYSTEM IS IN A FAVORABLE ENVIRONMENT
OF MODERATE (15 TO 20 KNOT) VERTICAL WIND SHEAR (VWS) AND WHICH IS
OFFSET BY VERY GOOD POLEWARD OUTFLOW. HOWEVER, THERE APPEARS TO BE
DRY AIR ENTRAINMENT ALONG THE WESTERN SIDE OF THE SYSTEM, LIMITING
DEVELOPMENT. TY 02W IS SLOWLY TRACKING NORTHWESTWARD UNDER THE
STEERING INFLUENCE OF THE SUB-TROPICAL RIDGE (STR) TO THE EAST.
3. FORECAST REASONING.
A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
B. TY HIGOS WILL CONTINUE TO TRACK TO THE NORTHWEST UNDER THE
STEERING INFLUENCE OF THE STR. WHILE CONDITIONS ARE SOMEWHAT
FAVORABLE, FURTHER INTENSIFICATION OF THE SYSTEM IS NOT LIKELY, WITH
THE SYSTEM SLOWLY WEAKENING AS IT ROUNDS THE STR AXIS. OVERALL MODEL
GUIDANCE IS IN GOOD AGREEMENT THROUGH TAU 48 LENDING TO HIGH
CONFIDENCE FOR THIS PERIOD OF THE
FORECAST.
C. IN THE EXTENDED TAUS, EXPECT RAPID DISSIPATION OF THE SYSTEM
AS VWS INCREASES NORTH OF THE 18TH PARALLEL AND THE SYSTEM SPEEDS UP
NORTH OF THE STR. THE SYSTEM WILL BE FULLY DISSIPATED BY TAU 96.
MODEL GUIDANCE HAS COME IN BETTER AGREEMENT OVER THE LAST 6 HOURS
WHICH LEADS TO AN OVERALL HIGH CONFIDENCE IN THE JTWC FORECAST
TRACK, WHICH IS PLACED CLOSE TO THE MULTI-MODEL CONSENSUS.//
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